Actually, The LabelClass does not provide any way to prioritize labeling or any ability to adjust the internal JS API conflict rules. So there is no coding that can be done to fix what you are encountering.

If there is a conflict between labels (they might overlap due to the reduced available space) the label will not be shown. You could try to reduce the size of the font, but other alternative would probably require some programming.

Actually, The LabelClass does not provide any way to prioritize labeling or any ability to adjust the internal JS API conflict rules. So there is no coding that can be done to fix what you are encountering.